1. Field of the Disclosure
The present disclosure relates to a circuit breaker, and particularly, to a circuit breaker capable of precisely determining a size of a target alternating current (abbreviated as AC hereinafter) component, even if a voltage detection signal or a current detection signal includes noise.
2. Background of the Disclosure
A detecting circuit for a circuit breaker in accordance with the related art will be explained with reference to FIGS. 1 to 3.
FIG. 1 is a block diagram illustrating a configuration of a detecting circuit for a circuit breaker in accordance with the related art. As shown in FIG. 1, the detecting circuit for a circuit breaker includes a detection sensor 20 configured to detect a voltage or a current on an AC circuit; a peak level detector 21 connected to an output terminal of the detection sensor 20, and configured to detect a peak level of a voltage detection signal on the AC circuit or a current detection signal on the AC circuit output from the detection sensor 20; and a comparator 22 connected to an output terminal of the peak level detector 21, and configured to compare an output signal from the peak level detector 21 with a reference voltage.
As shown in FIG. 2, a wave of voltage detection signal (Va) or a current detection signal, which is detected from an AC circuit by the detection sensor 20, shows a waveform which fluctuates up and down based on a Root Mean Square (abbreviated as RMS hereinafter) value wave (Vrms), due to noise included therein.
A peak level of the detection signal (Va) is extracted by the peak level detector 21 of a next stage.
Then the peak level of the detection signal is compared with a reference voltage by the comparator 22 of a next stage. If the peak level of the detection signal is equal to or larger than the reference voltage, the comparator 22 outputs a signal of a high level. The output signal of a high level (Vout) has a waveform shown in FIG. 3.
A circuit breaker 10 of FIG. 1 operates to a breaking position (‘trip’ position), by the signal of a high level, which is output from the comparator 22.
However, the conventional detecting circuit for a circuit breaker may have the following problems.
Firstly, the detection signal (Va) shown in FIG. 2, which has been distorted due to harmonic noise such as switching noise from a diode or a transistor, is compared with a reference voltage of the comparator 22. Then the compared signal is output as an output signal (Vout) shown in FIG. 3. This may cause a malfunction of the circuit breaker 10.